Egg Boiling Time Calculator
Time boiled eggs to the exact doneness you want — from runny soft-boiled to firm hard-boiled, adjusted for egg size and starting temperature.
How it works
time = base doneness time × size factor − 1 min (if room temperature) · minimum 1 min
Egg timing is really about how far heat has penetrated to the yolk, so the two things that move the clock are the egg's mass and its starting temperature. These times assume you lower the egg into water already at a rolling boil, which gives a consistent, repeatable start — unlike bringing eggs up from cold water, where the result depends on how fast your stove heats. A larger egg needs a bit longer; a room-temperature egg needs about a minute less. Always shock the eggs in ice water afterward to stop the cook and make peeling far easier.
Worked example
For a jammy large egg from the fridge, lower it into boiling water and cook 7 minutes. Want the same yolk from an extra-large egg? The size factor pushes it to about 8 minutes. Chill immediately — the residual heat of a hot egg will keep firming the yolk for another minute or two.
Frequently asked questions
Cold-water start or boiling-water start?
A boiling-water start is more repeatable because the timing does not depend on your burner. A cold-water start can peel a touch more easily but you have to time from when it reaches a boil, which varies.
Why do fresh eggs peel badly?
Very fresh eggs have a low internal pH that makes the white cling to the membrane. Eggs a week or two old peel more cleanly, and a hard ice-bath shock after cooking helps a lot.
Does altitude change the time?
Yes — water boils cooler at altitude, so add roughly 1 minute per 3,000 feet above sea level to reach the same doneness.
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This calculator is for educational purposes. Double-check important results before acting on them.